EP0502218A1

EP0502218A1 - Apparatus for producing stabilizing mixture

Info

Publication number: EP0502218A1
Application number: EP90401844A
Authority: EP
Inventors: Toshinobu c/o Toyo Denki Ind. Co. Ltd. Araoka
Original assignee: Toyo Denki Industrial Co Ltd
Current assignee: Toyo Denki Industrial Co Ltd
Priority date: 1989-01-27
Filing date: 1990-06-27
Publication date: 1992-09-09
Also published as: JP2531774B2; JPH02200994A; CA2019975C; CA2019975A1

Abstract

An apparatus for producing stabilizing mixture is diclosed. The apparatus is characterized in that an underwater pump (12) provided with a suction port (16) and at least one discharge port (17b) is disposed in a stirring water tank (10), that suction port and the discharge port are opened into the stirring water tank, and that the other end of a bentonite intake pipe (19b) having one end connected to a supply source (21) for bentonite or the like is connected to the discharge port whereby the bentonite or the like can be sucked into the discharge port due to the negative pressure generated in the discharge port when the underwater pump is driven and vigorously mixed with water to produce a stabilizing mixture of uniform concentration.

Description

STATE OF ART

The present invention relates to an apparatus for producing stabilizing mixture in which a stabilizing mixture of uniform density used in excavation work can be produced readily in volume.

BACKGROUND OF INVENTION

In order to smoothly carry out excavation work for well-digging, lower holes for piles and the like, the excavation work is carried out while pouring into an excavated hole a stabilizing mixture in slurry form produced by mixing stabilizing powder material such as bentonite and water.
As the apparatus for producing stabilizing mixture of the type as described, stabilizing mixture producing apparatuses B and C shown in Figs. 6 and 7 are known.
First, the stabilizing mixture producing apparatus B shown in Fig. 6 will be described. The apparatus B is composed of a density regulating tank 60 interiorly provided with a stirring pump 61 and a mud discharging pump 62, and a mud preparing tank 63 interiorly provided with a mixer 64.
In this arrangement, first, bentonite 65 and water 66 are charged into the mud preparing tank 63, which are stirred by the mixer 64 to produce stabilizing mixture or stabilizer 67.
The stabilizing mixture 67 is charged into the density regulating tank 60 and stirred by the stirring pump 61, and the stabilizing mixture 67 formed into a uniform composition by said stirring can be charged into an excavated hole not shown through a mud transferring pipe 68.
The stabilizing mixture producing apparatus C shown in Fig. 7 will be described. The apparatus C is composed of a stirring and mud preparing pump 69 which is larger than the aforementioned stirring pump 61 and a mud discharging pump 62.
In this arrangement, bentonite 65 is charged into the density regulating tank 60 filled with water 66, which are stirred and prepared by the stirring and mud preparing pump 69. The stabilizing mixture 67 produced into a uniform composition by said stirring and mud preparation is charged into an excavated hole not shown through the mud transferring pipe 68.
However, the above-mentioned stabilizing mixture producing apparatuses B and C still have tasks to be solved as follows.

(1) In the stabilizing mixture producing apparatus B shown in Fig. 6, an expensive mixer 64 is required, and therefore the apparatus B itself is costly. In addition, two processes are employed in which after the mud has been prepared by the mud preparing tank 63, the mud is regulated by the density regulating tank 60. Therefore, it takes a considerable time to produce the stabilizing mixture 67 having a uniform composition or no segregation.
(2) On the other hand, in the stabilizing mixture producing apparatus C shown in Fig. 7, the bentonite is directly charged into the density regulating tank 60 without using the mud preparing tank 63 in advance, and thereafter, stirring and mud-preparation take place by use of only one stirring and mud preparing pump 69. Therefore, the bentonite 65 becomes dissolved incompletely so that a large quantity of bentonite 65 remains on the bottom of the density regulating tank 60, and particles of the bentonite 65 in the stabilizing mixture 67 become increased in size.

Accordingly, it is an object of the present invention to provide a stabilizing mixture producing apparatus which can solve the above-described problems.
In summary, the present invention provides an apparatus for producing stabilizing mixture comprising a stirring water tank containing water therein, an underwater pump submerged in the water in the stirring water tank, the pump having a suction port and at least one discharge port, the suction port and the discharge ports being opened into the water in the stirring water tank, and a stabilizing material intake pipe having one end connected to a supply source for stabilizing material and the other end connected to the discharge port, whereby the stabilizing material can be sucked into the discharge port due to the negative pressure generated in the discharge port when the underwater pump is driven and vigorously mixed with water to produce a stabilizing mixture of uniform concentration.
With the above-described construction, the present invention has the following effects:

(1) In the present invention, when the underwater pump is actuated, water is sucked from the suction port and water is discharged from the discharge ports. Negative pressure produced by said discharge of water is utilized, that is, by the ejector effect, powdery stabilizing material is sucked into the discharge ports through an intake pipe for bentonite or the like and mixed with the discharge water along with air, after which the thus mixed liquid can be discharged out of the discharge ports.
In the above-described operation, the bentonite or the like is readily dissolved into water when the former is mixed with the discharge water, and thereafter, it is discharged from the discharge ports and stirred throughout.
Accordingly, a large quantity of stabilizing mixture having a uniform concentration can be produced rapidly.
(2) Furthermore, since the stabilizing mixture discharged out of the discharge ports has air mixed therein, a powerful stirring flow can be formed within the stirring water tank, and the concentration of the stabilizing mixture can be made further uniform.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a front view in section of one embodiment of a stabilizing mixture producing apparatus according to the present invention.
Fig. 2 is a plan view of the apparatus shown in fig. 2.
Figs. 3 and 4 are a front view in section and a plan view, respectively, of another embodiment according to the invention.
Fig. 5 is a front view in section of a modification of the above embodiment shown in fig. 3 and 4.
Figs. 6 and 7 are front views in section of a conventional stabilizing mixture producing apparatus.

DETAILED DESCRIPTION OF THE DISCLOSURE

The structure of the stabilizing mixture producing apparatus A according to the present invention will be specifically described by reference to the embodiments shown in the drawings.
In Figs. 1 and 2, reference numeral 10 designates a stirring or agitating water tank, which is interiorly filled with water W to a fixed height H.
An underwater pump 12 is stood upright within the stirring water tank 10 and above the central portion of a bottom plate 11.
The underwater pump 12 comprises, as shown in Fig. 1, an impeller casing 13 which encases an impeller 13a rotatably therein, and a motor casing 14 arranged adjacent to said impeller casing 13 and housing therein a motor 14a connected to the impeller 13a to rotate the latter.
Rererence numeral 15 designates a support base on which the underwater pump 12 is placed and supported.
With the above-described arrangement, the impeller casing 13 is provided in its front central bottom portion with a suction port 16 and in its outer peripheral edge with a plurality (three in this embodiment) of discharge ports 17a, 17b and 17c, as shown in Figs. 1 and
Mounted on the discharge ports 17a, 17b and 17c are trumpet- like jet nozzles 18d, 18e and 18f, respectively, to bring discharge openings 18a, 18b and 18c to a position away from the underwater pump 12.
As will be described hereinbelow, the discharge ports 17a, 17b and 17c are used to discharge a stabilizing mixture which is a mixture of bentonite, air and water into the stirring water tank 10.
In this embodiment, bentonite is used as a powdery stabilizing material.
The discharge direction of the discharge ports 17a, 17b and 17c extends in a tangential direction of the outer peripheral edge of the impeller 13a to provide smooth discharge and transfer of the stabilizing mixture.
That is, as shown in Figs. 1 and 2, bottom ends of a plurality of lower bentonite intake pipes 19a, 19b and 19c are communicated with and connected to base ends of the discharge ports 17a, 17b and 17c, and upper ends of the lower bentonite intake pipes 19a, 19b and 19c are communicated with and connected to a distributing tube 20.
Communicated with and connected to the distributing tube 20 is one end of an upper bentonite intake pipe 19d, which in turn has the other end thereof inserted through a filter 23 into bentonite 22 within a bentonite container 21 as a supply source for bentonite or the like provided externally of the stirring water tank 10.
The upper bentonite intake pipe 19d is provided in its midst with an opening and closing valve 19e. The valve 19e is opened and closed to thereby assume a bentonite mixing form suited to the conditions in the operation or construction site, that is, supplying of bentonite 22 exclusively, supplying of air exclusively, or supplying of neither bentonite 22 nor air.
As shown in Figs. 1 and 2, at one corner of the stirring water tank 10 is disposed a mud transfer pump 40 provided at its lower portion with a suction port. One end of a bendable mud transfer hose 42 is connected to a discharge port 41 provided at an upper portion of the pump 40, the other end of the hose 42 being inserted or extended into a desired excavation hole.
As shown in Fig. 1, an opening and closing valve 43 is provided on the hose 42.
Next, the manner of using the stabilizing mixture producing apparatus A having the above-described structure will be described with reference to Figs. 1 and 2.
First, the valve 19e provided in the midst of the upper bentonite intake pipe 19d is opened and the valve 43 provided on the hose 42 is closed. The underwater pump 12 and the mud transfer pump 40 are driven.
When the pumps 12 and 40 are driven, the impeller 13a within the impeller casing 13 rotates, whereby water is sucked from the suction port 16 into the impeller casing 13.
The water flown into the impeller casing 13 is discharged or jetted into the stirring water tank 10 through the discharge ports 17a, 17b and 17c and the jet nozzles 18d, 18e and 18f from the casing 13.
In the discharging operation, negative pressure is generated within the discharge openings 18a, 18b and 18c.
Due to this occurrence of negative pressure, that is, the ejector effect, powdery bentonite 22 within the bentonite container 21 is jetted along with air into the discharge ports 17a, 17b and 17c through the bentonite intake pipe 19d, the distributing tube 20 and the lower bentonite intake pipes 19a, 19b and 19c in said order and mixed with discharging water flowing through the discharge ports 17a, 17b and 17c to produce a mixed liquid.
Thereafter, the mixed liquid is powerfully jetted into the stirring water tank 10 from the jet nozzles 18d, 18e and 18f.
In the above-described operation, the bentonite 22 is instantly dissolved with the discharging water and then is vigourously discharged from the jet nozzles 18d,18e and 18f in all radial directions through the discharge ports 17a, 17b and 17c and stirred throughout within the stirring water tank 10.
Accordingly, a large quantity of stabilizing mixture having a uniform concentration without any segregation can be produced rapidly.
In the present invention, since the stabilizing mixture discharged out of the discharge ports 17a, 17b and 17c is mixed with air, a powerful stirring flow can be formed within the stirring water tank 10 to further promote making of concentration of the stabilizing mixture uniform.
Thereafter, when the valve 43 provided in the mud transfer hose 42 is opened, the stabilizing mixture produced in the above-described procedure is supplied rapidly and positively to the desired excavated holes or the like through the hose 42 from the discharge ports 41 of the pump 40.
Moreover, the above-described bentonite mixing and stirring action is continuously carried out simultaneously with the aforesaid mud transferring action. Therefore, the mud transferring action can be continuously carried out while uniformly maintaining the concentration of the stabilizing mixture to enhance the efficiency of the excavation work.
While in the above-described embodiment, the underwater pump 12 is merely provided with the impeller 13a, it is to be noted that an output shaft of the motor 14a with the impeller 13a may be extended downward, and a cutter may be mounted on said extended portion.
In this case, mixing of the bentonite 22 and water can be further promoted, particles of the bentonite 22 can be further made finer, and the stabilizing mixture can be made further uniform.
Next, a further embodiment of the stabilizing mixture producing apparatus A of the present invention will be described with reference to Figs. 3 and 4.
The present embodiment is substantially characterized by a structure which allows the underwater pump 12 to have not only the stirring function but also the mud transferring function. Parts of the same construction as those of the stabilizing mixture producing apparatus A shown in Figs. 1 and 2 are indicated by the same reference numerals.
In the present embodiment, as shown in Figs. 3 and 4, a discharge port 17c of the underwater pump 12 has its extreme end bended upwardly, to which is connected a lower end of the mud transfer pipe 24. One end of a bendable mud transfer hose 25 is connected to the upper end of the pipe 24, and the other end of the hose 25 is inserted into the desired excavated hole.
As shown in Fig. 3 an opening and closing valve 26 is provided at the upper portion of the mud transfer pipe 24.
Due to the above-described structure, the stabilizing mixture having a uniform concentration can be produced by action, similar to the aforementioned embodiment. In addition, the bentonite mixing and stirring action is carried out continuously simultaneously with the mud transferring action. Namely, the mud transferring action can be continuously carried out while maintaining the concentration of the stabilizing mixture uniform to improve the efficiencey of excavating work.
Furthermore, in the present embodiment, since charging of bentonite 22, mud-preparation, stirring and mud transferring can be carried out by use of a single underwater pump 12, the stabilizing mixture producing apparatus A can be manufactured inexpensively.
Next, a modification of the above described embodiment will be described with reference to Fig. 5.
This modification is characterized in that a supply source for bentonite or the like may be residual bentonite which floats in the upper part of an excavated hole, and such floating residual bentonite can be transferred from an old excavated hole to a new excavated hole.
That is, in Fig. 5, reference numerals 30 and 31 designate new and old excavated holes, respectively, a foundation 33 of concrete is placed within the old excavated hole 31, and the residual or excessive bentonite 22 floats thereabove.
On the other hand, no foundation is placed in the new excavated hole 30.
In the stabilizing mixture producing apparatus A according to the present embodiment, one end of the lower bentonite intake pipe 19c is inserted into the bentonite 22 within the old excavated hole 31, and one end of the mud transfer hose 25 is inserted into the new excavated hole 30.
With the above-described structure, the negative pressure produced by the underwater pump 12 can be utilized similarly to the aforementioned embodiments to suck the bentonite 22 from the old excavated hole 31 and the bentonite 22 can be mixed and stirred with water efficiently and uniformly within the stirring water tank 10 to produce stabilizing mixture.
The stabilizing mixture can be continuously supplied to the new excavated hole 30. And, the thus obtained stabilizing mixture can be coated on the inner surfaces of the new excavated hole 30 to thereby positively prevent the excavated walls from being collapsed.
In Fig. 5, reference numeral 32 designates a concrete charging device.
While in the embodiments shown in Figs. 1 to 5, the bentonite 22 has been used as a powdery stabilizing material to be mixed into water, it is to be noted that the stabilizing mixture producing apparatus according to the present invention can use other materials, for example, such as cement, which can be mixed with water to thereby produce a slurry.

Claims

An apparatus for producing stabilizing mixture comprising
a) a stirring water tank (10) containing water therein,

b) an underwater pump (12) submerged in said water in said stirring water tank, said pump having a suction port (16) and at least one discharge port (17a,17b,17c), said suction port and said dis-ports being opened into said water in said stirring water tank, and

c) a stabilizing material intake pipe (19d,19b,19c) having one end connected to a supply source (21) for stabilizing material and the other end connected to said discharge port,
whereby said stabilizing material can be sucked into said discharge port due to the negative pressure generated in said discharge port when said underwater pump is driven and vigorously mixed with water to produce a stabilizing mixture of uniform concentration.
An apparatus for producing stabilizing mixture according to claim 1, wherein said pump (12) is provided with a plurality of said discharge ports (17a,17b,17c) and said stabilizing material intake pipe has said other end thereof connected to at least one of said discharge port.
An apparatus for producing stabilizing mixture according to claim 1, wherein a stabilizing mixture transfer pump (40) is disposed in said water in said stirring water tank.
An apparatus for producing stabilizing mixture according to claim 1, wherein one of said discharge ports is connected with one end of a stabilizing mixture transfer pipe which has the other end thereof communicated with a place which requires said stabilizing mixture.